Bump dexidp/dex from v2.45.1 to v2.46.0 in /dockerfiles/test-dex

Bumps [dexidp/dex](https://github.com/dexidp/dex) from v2.45.1 to v2.46.0.
- [Release notes](https://github.com/dexidp/dex/releases)
- [Commits](https://github.com/dexidp/dex/compare/v2.45.1...v2.46.0)

---
updated-dependencies:
- dependency-name: dexidp/dex
  dependency-version: v2.46.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

dockerfiles/test-dex/Dockerfile

@@ -1,4 +1,4 @@
 # Copyright 2021-2024 the Pinniped contributors. All Rights Reserved.
 # SPDX-License-Identifier: Apache-2.0
 
-FROM ghcr.io/dexidp/dex:v2.45.1
+FROM ghcr.io/dexidp/dex:v2.46.0